Data Leakage through Self-Terminated Write Schemes in Memristive Caches

Memory cells in emerging non-volatile resistive memories often have asymmetric switching properties, where reliable write operations are achieved by setting the write period to a fixed value. To improve their performance and energy efficiency, self-terminating write schemes have been proposed, in which the write signal is stopped after the required state change has been observed. In this work, we show how this data-dependent write latency can be exploited as a side-channel in multiple ways to unveil restricted memory content. Moreover, we discuss and evaluate potential approaches to address the issue.